Hi guys I'm after a orp meter,which one would people recommend? Is it better to have a dedicated meter for this or one which does ph,tds,ect from one unit?
Thanks
Al
Orp meter
Moderators: B.Scott, vippymini, Gazza, Manky Sanke
Re: Orp meter
Al go for the pinpoint I had two of these never let me down
dunc
dunc
Re: Orp meter
ok thanks Duncan,I'll have a look at those! 
Al
Al
Re: Orp meter
As Duncan says pinpoint all the way mate
Re: Orp meter
Cheers stu!do you use it to maintain your pond or only when using pp ect?
Thanks
Al
Thanks
Al
-
Manky Sanke
- Site Admin
- Posts: 554
- Joined: Sun Apr 16, 2006 10:24 am
Re: Orp meter
Count me as a vote for Pinpoint, Al,
You can buy cheaper but the quality of Pinpoint meters is hard to beat for the price.
If you get one, I would also buy a few sachets of their 400 mV calibration solutions rather than use cheaper solutions that give 200 mV values because 400 mV is much closer to the 450 mV target recommended for potassium permanganate treatments and, the nearer you can calibrate any meter to the value you want to measure, the more certain you can be of the accuracy of readings at that value. (That makes sense to me but ask if it needs further clarification).
Although Pinpoint say they shouldn't be stored, I've always found that ORP calibration solutions can be stored and reused if they are kept in a cool, dark place in a tightly sealed container that is small enough to have very little room for air after the solution has been poured in. The main point is to GENTLY but thoroughly rinse and dry the probe before calibrating so as not to introduce any water or other contamination into the solution.
BUT, as a sensible precaution, use a fresh solution to double check the accuracy of the calibration before you use it to measure the pond ORP during a potassium permanganate treatment.
As to how often you should check the pond ORP, that's a matter of choice. Some hobbyists argue that they never need to check water parameters until the fish tell them that something is wrong, (sometimes emphasising the urgency of the situation by dying!!!). It makes better sense to check parameters every week because that will give an early indication of anything beginning to go wrong before it has time to become serious. ORP isn't the most important parameter to measure on a pond but if it gives you a sense of security or confidence there is no reason why you shouldn't check it regularly.
You can buy cheaper but the quality of Pinpoint meters is hard to beat for the price.
If you get one, I would also buy a few sachets of their 400 mV calibration solutions rather than use cheaper solutions that give 200 mV values because 400 mV is much closer to the 450 mV target recommended for potassium permanganate treatments and, the nearer you can calibrate any meter to the value you want to measure, the more certain you can be of the accuracy of readings at that value. (That makes sense to me but ask if it needs further clarification).
Although Pinpoint say they shouldn't be stored, I've always found that ORP calibration solutions can be stored and reused if they are kept in a cool, dark place in a tightly sealed container that is small enough to have very little room for air after the solution has been poured in. The main point is to GENTLY but thoroughly rinse and dry the probe before calibrating so as not to introduce any water or other contamination into the solution.
BUT, as a sensible precaution, use a fresh solution to double check the accuracy of the calibration before you use it to measure the pond ORP during a potassium permanganate treatment.
As to how often you should check the pond ORP, that's a matter of choice. Some hobbyists argue that they never need to check water parameters until the fish tell them that something is wrong, (sometimes emphasising the urgency of the situation by dying!!!). It makes better sense to check parameters every week because that will give an early indication of anything beginning to go wrong before it has time to become serious. ORP isn't the most important parameter to measure on a pond but if it gives you a sense of security or confidence there is no reason why you shouldn't check it regularly.
Re: Orp meter
Makes good sense,cheers Manky!